Video Tools

About Video Tools

A 4K video from a GoPro is 1.2GB. A Zoom recording in MP4 is 450MB. A screen recording for a tutorial is 800MB. Video files are large, and the tools to process them traditionally require desktop software like Adobe Premiere or HandBrake. This category brings video processing to your browser using FFmpeg compiled to WebAssembly. The tools handle compression, format conversion (MP4, WebM, MOV, AVI, MKV, FLV, WMV, TS, M4V), trimming, merging, speed adjustment, watermarking, rotation, and audio extraction. Processing happens entirely on your device: no upload, no queue, no subscription.

When to Use These Tools

• •Compressing a 1.2GB 4K GoPro video to 120MB at 1080p for YouTube upload
• •Converting MKV downloads to MP4 for Apple TV and smart TV compatibility
• •Trimming a 45-minute Zoom recording to the 8-minute segment that matters
• •Merging multiple video clips into a single file for a compilation video
• •Extracting the audio track from an MP4 video as an MP3 file for podcast editing
• •Adding a logo watermark to a batch of tutorial videos before publishing

Benefits

• •Compression uses FFmpeg CRF encoding with H.264 or H.265 codec, achieving 50 to 80% file size reduction
• •Format conversion supports 15 container and codec combinations including remux (no re-encode, seconds) and full re-encode
• •Trim tool uses stream copy when possible for instant cuts with zero quality loss at keyframe boundaries
• •Merge tool concatenates video files with matching codecs without re-encoding for fastest processing
• •Speed adjustment supports 0.25x to 4x playback speed with optional pitch correction for audio
• •Watermark tool overlays text or image logos with position, opacity, and scale controls

Tips for Best Results

• •Use H.264 codec with CRF 23 for general-purpose video compression: it plays on virtually every device and browser
• •When converting MKV to MP4, check if a remux is available first: if the video stream is already H.264, remuxing takes seconds with zero quality loss
• •For trimming, set cut points near scene changes: FFmpeg can cut precisely at keyframes without re-encoding, but cuts between keyframes require re-encoding
• •Compress video before uploading to social media: platforms re-encode anyway, so starting smaller saves upload time
• •When merging videos, ensure all source files have the same resolution, framerate, and codec for clean concatenation
• •Extract audio as MP3 at 192 kbps for general use, or as AAC at 256 kbps for Apple ecosystem compatibility

Practical Examples

Common Mistakes to Avoid

• •Setting CRF below 18 for compression: file sizes balloon with no perceptible quality improvement over CRF 18
• •Re-encoding video when a remux would suffice: if the codec is already H.264, changing the container from MKV to MP4 takes seconds with no quality loss
• •Merging videos with different resolutions or framerates: this causes stuttering, desync, or failure. Normalize all source files first
• •Using H.265 for web video without checking browser support: Safari supports it, but Chrome and Firefox have limited support. H.264 is the safe default
• •Forgetting that trimming between keyframes requires re-encoding: if the trim tool needs to re-encode, it will take longer and may slightly reduce quality

References and Further Reading

• •FFmpeg Documentation
• •H.264 Encoding Guide - FFmpeg Wiki
• •Video Codec Browser Support - Can I Use
• •MP4 Container Specification - ISO 14496-14

Conclusion

Video files are the largest media files most people work with, and having browser-based tools to compress, convert, and trim them saves time and storage. The tools above handle every common video task using FFmpeg in WebAssembly. Pick the tool you need, drag in your video, and download the result.